Telescopic tuning mechanism



G. E. MURPHY TELESCOPIC TUNING MECHANISM Oct. 27, 1936.

, 1956 5 Sheets-Sheet .1

Filed June 9 'll-Am" Filed June 9, 193e 5 sheetshle'et 2" Oct, Z7, 1936. G. E. MURPHY TELESCOPIC TUNING MECHANISM 5 Sheets-Sheet 3 Filed June 9, 1956 Oct. 27, 1936. G. E. MURPHY TELESCOPIC TUNING MECHANIVSM Filed June 9, 195e ssheets-sheet 4 v G. E. MURPHY TELESCOPIC TUNING MECHANISM Oct. 27, 1936.

Filed June 9, 1936 5 Sheets-Sheet 5 'yllllllllllllilllllllllll Patented Oct. 27, 1936 UNITED STATES ATENT crFlcE 20 Claims.

This invention is a novel telescopic tuning mechanism for radio receiving apparatus, in which the wave scale sheet is provided with a plurality of parallel radio wave scales disposed one above the other; and the principal object of the invention is to provide means whereby the reading of anyone of the wave scales may be visualized through or upon a wave scale window in the radio cabinet as the radio is tuned to that particular wave length, the said means including a sight barrel swingably mounted between the wave scale and window and adapted to be pivoted as the radio apparatus is tuned so as to focus the lens barrel on any one of the wave scales of the sheet.

l5 By the above construction a maximum number of wavelengths in a minimum wave scale sheet area may be provided thereby permitting the tuning range of the radio receiving apparatus to be eX- panded; and by the use of a magnifying lens in the sight barrel and a lamp behind the wave scale sheet, if transparent, the enlarged projected reading of the scale for any tuned position may be accurately ascertained or visualized.

Other minor objects of the invention will be 7, hereinafter set forth.

I will explain the invention with reference to thev accompanying drawings, which illustrate various practical embodiments thereof, to enable those familiar with the art to adopt and use the same; and will summarize in the claims the novel features of construction, and novel combinations of parts, for which protection is desired.

In said drawings:-

Fig. 1 is a vertical section through one form of tuning mechanism showing the adjacent portions of the front wall of the radio cabinet.

Fig. 2 is -a front elevation thereof, with the front wall of the cabinet removed.

Fig. 3 is a front elevation of a section of the front wall of the radio panel showing the relative positions of the wave scale window and the tuning knobs for the mechanism shown in Figs. 1 and 2.

Fig. 4 is an enlarged end elevation of the wave scale sheet, detached.

Figs. 5, 5a, 5b, 5c, 6 and 7 are enlarged longitudinal sections through modified sight barrels.

Fig. 8 is an end elevation showing a modified arrangement of the mounting of the fixed marker 5o associated with the wave scale sheet and lamp casing.

Fig. 9 is a vertical section through a modification showing independent means for focusing or setting the sight barrel.

55 Fig. 10V is a vertical section through the sight (Cl. 11G-124.1)

barrel and adjacent parts showing a modied form of mechanism.

Fig. 11 is a front elevation of the modification shown in Fig. 10 with the front wall of the cabinet removed. 5 Fig. 12 is a vertical section adjacent the sight barrel through a still further modified form of mechanism.

Fig. 13 is a front elevation of the mechanism shown in Fig. 12, with the front wall of the cabi- 10 net removed.

Fig. 14 is a front elevation of a portion of the front wall of the cabinet indicating the relative positions of the sight openingand the two knobs for operating the tuning mechanism, for the 15 modication shown in Figs. 12-13.

Fig. l5 is a vertical section somewhat similar to Fig. 12 showing a still further modication of the mechanism. l

Fig. 16 is a front elevation of the mechanism shown in Fig. 15, with the front wall of the cabinet removed.

Fig. 17 is a plan View of the mechanism shown in Fig. 16.

Fig. 18 is a vertical section through a still further modification of the mechanism; and

Fig. 19 is a plan view of the front wall of the cabinet showing the control knobs and sight opening for the modification shown in Fig. 18.

As shown in Figs. 1, 2, and 3, within the radio cabinet adjacent the front wall 29 is a front supporting panel 28, behind which is a rear supporting panel Il, both panels being xedly mounted in any desired manner in spaced relation, and carrying the working parts of the mechanism.

The upper edge of rear panel Il is bent rearwardly, then upwardly and outwardly to form an oifset guide I3 for receiving the rear edge of a substantially inverted T-shape rack bar, the front edge of which is retained in guide i3 by means of 40 plates I5 having rearwardly directed iianges 15a at their upper ends, said plates l5 being secured by screws I6 o1' the like to panel Il with spacing blocks interposed between the plates and panel. Rack bar M may be moved laterally in its guides 4,5 and the underside of the bar is provided with teeth Ma, meshing with a gear wheel i8 xedly mounted upon the condenser shaft I9 of the radio apparatus, the shaft I9 extending through the panels Il and 28 and through the front wall 29 50 of the cabinet and carrying a knob 30, whereby rotation of the knob will shift the rack bar in its guides.

Fixedly mounted upon the top of rack bar I4 near the ends thereof are substantially arcuate slotted arms I for holding a wave scale sheet 9, the tops of arms I9 being co-nnected by a spacer bar |I. The axis of curvature of arms I0 as shown in Fig. 1 is disposed substantially in the plane of an opening 3| in the front panel 28 through which the front end of the sight barrel I (hereinafter described) extends, said opening 3| being disposed directly behind the window opening 29a, in the front Wall 2S of the cabinet. The wave scale sheet 9 carries any desired number of superimposed wave scales, five bands being shown in Fig. 2 marked 8a, 9b, 9c, 9d, and 9e respectively. The respective wave scales of sheet 9 may be of contrasting colors; and the scales extend substantially the full length of sheet 9, and are separated by bands 9x. The wave scale sheet 9 is preferably of transparent material, but the scale markings and bands 9x are non-transparent.

Preferably the wave scale sheet 9, instead of being strictly arcuate, is formed of a series of plane surfaces as shown in Fig. 4, one for each wave scale 9a to 9e inclusive, with the center of each plane surface tangent to the arc of the circle X whose axis is coaxial with the axis of swing of the sight barrel I. Sharper focusing may be obtained with this construction, since each wave scale will be disposed normal to the axis of the lens barrel I. If the wave scales were arcuate the upper and lower portions thereof would be blurred in case an inexpensive type of lens were used in the barrel I.

In rear of the sheet 9, and opposite opening 3| of panel 28, is a lamp casing 34 within which is an electric light bulb 33 or other source of illumination, said casing 34 having an arcuate front face conforming generally with the curvature of the wave sheet 9 and having a vertical slot (no-t shown) in its front face aligned with the vertical axis of opening 3| and of width equal to that of the adjacent end of the sight barrel I, whereby each of the wave scales Sai-9e inclusive will be illuminated at a point opposite the opening 3| but only the particular wave scale upon which the barrel I is focused will be visible through or upon the wave scale window 32 disposed over the opening 29a in wall 29.

Only indirect lighting of the wave scale sheet is shown in drawings, but direct lighting may be employed, so that the light will be reflected between the end of the barrel and the wave scale sheet.

The sight barrel (Figs. 1 and 2) is horizontally pivoted upon pins 3 disposed in the axis of curvature of arms I 0, so that the front end of the barrel is disposed within the opening 3| while its rear end is free to swing vertically so as to register with any of the wave scales 9w-9e inclusive of sheet 9. The lens barrel preferably contains a magnifying lens 2 in its front end for enlarging the reading of the illuminated portion of the wave scale upon which the barrel is focused.

The lens barrel as shown in Figs. 1 and 2 is in the form of a truncated pyramid same being of rectangular cross-section; however if desired, same may have a circular or other cross-section, and the shape of the lens 2 would be modified accordingly. In Fig. 5 the barrel Ia is shown as of truncated conical shape, utilizing a circular lens 2a in the outer end of the barrel; also a second smaller lens 2b, shown in dotted lines, in the barrel adjacent the smaller inner end, to provide for higher magnification. In Fig. 6 a further modified barrel Ib is shown in which the outer portion is extended through the opening 3| in panel 28, also through the opening 29a in the front wall 29 of the cabinet, the barrel termi nating closely adjacent the arcuate window 32. Lens 2 is mounted in the outer end of the barrel, but in addition a second lens may be mounted therein as in Fig. 5. In Fig. 7 a still further modication is shown in which the barrel Ic is of cylindrical shape with each end of equal diameter, and carries a lens 2c. The inner end of the barrel is provided with a transverse slot Id extending across the barrel at its center, the slot being of heighth equal to that of the individual wave scales 9ct-9c. The inside of the barrel is preferably painted black to showin vivid contrast the shades of colors used to denote the different wave scales .9a- 9e inclusive, and this feature combined with the use of different colored wave scales on sheet 9 greatly facilitates the proper tuning of the mechanism.

The marker 35 (Fig. 2) for the wave scales is of hair-like character and may be conveniently located at the vertical center of the inner end of the sight barrel. Markers centered at each end o-f the barrel may also be used in which case both markers would be brought into alignment when tuning, thereby resulting in greater accuracy. The marker at the outer end of the barrel may be located either behind, as at 35a: (Fig. 5a), or in front of lens 2, as at 35g/ (Fig. 5b) or may consist of a line 2x (Fig. 5c) marked on the lens 2 itself. A further modification would be to mount a marker 35a (Fig. 8) behind the wave scale sheet 9 upon the guide I3 of rack bar I4, the marker being arcuate in shape and in close proximity to the scale sheet. The reflection of the marker from lamp 33 would show as a shadow band across the Wave scale being tuned.

The swinging movement of the sight barrel is accomplished by an elevating lever 4 (Figs. 1-2) pivoted at 8 upon a supporting bracket 5 mounted upon the panel 28 below the opening 3|, the upper end of lever 4 supporting the barrel which rests thereon. The lower end of lever 4 engages the irregularly contoured face 2| of a gear 2|) loosely journaled upon condenser shaft I9 so as to rotate freely thereon. Below shaft I9 is journaled a shaft 22 of the wave band switch (not shown), which shaft extends through the front wall 29 of the cabinet and carries a knob 25 on its outer end. On shaft 22 is a gear 23 meshing with gear 28 whereby as knob 25 is turned the gear will be rotated to bring different portions of the irregularly contoured face 2| into engagement with lever 4 to cause same to raise or lower the barrel. A spring 6 connecting the lower portion of lever 4 with the bracket 5 yieldably maintains the lower end of said lever in constant engagement with the contoured face 2| of gear 20. If desired, instead of spring 6, a spring may be disposed around the bearing 8 of the lever 4, or arranged in any other desired manner.

In Fig. 3 the knob 25 is shown as having a pointer a which cooperates with positions marked "1, 2, 3, 4, 5, on the wall 29 of the cabinet to denote the proper setting of knob 25 to focus the barrel on any of the wave scales 9ct-9e. The setting of knob 25 also actuates the wave band switch shaft 26 which is disposed below shaft 22, shafts 22 and 26 carrying intermeshing gears 24 and 21.

Thus the turning of knob 25 sets the wave band switch (not shown) through shaft 26 and focuses the barrel I on the related Wave scale .9a-9e inclusive, while the turning of knob 30 actuates the condenser shaft I9 and correspondingly moves the scale sheet 9 to the right or left across the inner end of the barrel. In Fig. 1 the lens barrel (shown in full lines) is focused on the right hand end of wave scale 9e, while in theposition shown in dotted lines, the lens barrel is focused on wave scale 9a. Lines A-A in Figs. l and 3 show the area of the projection of wave scale 9e on window 32; while the area of projection of the wave scale 9a would be bounded by thelines B-B (Fig. 1). 'Ihe areas of the projections of the other wave scale 9b-9d inclusive would lie between lines A and B.

Window 32 may be with or without glass. If glass is used, it may be clear or frosted. If clear, it may be curved or straight, and the scale would be seen by looking into the lens barrel with the eye, the lens and the scale o-n a line. Preferably ground glass is used, upon which the scale would be reflected and the window 32 is curved as shown to permit a View from any angle.

Independent control of barrel I may be provided by using a separate knob 92 (Fig. 9), which arrangement would eliminate members 2i), 2l, 22, 23,` 2li, and 21 of Fig. l., a wave band switch knob 53 being mounted directly on the extended end of shaft 23; In this construction the position oflens barrel I is governed by the threaded or spirally channeled rod 4I pressing against the lower end of elevating lever l, said rod being moved inwardly or outwardly by rotation thereof in its correspondingly threaded or spirally grooved bearing ila which is mounted on panel 28, the knob 52 serving as a means for rotating same. The pitch ofthe threads or spirals of rod 4I is determined by the degrees in the arc of rotation of rod M, indicia on the wall of the cabinet adjacent the knob cooperating with a pointer on the knob (similar to parts 25-25a, Fig. 3) being provided for indicating the proper settinglof knob ft2 with respect to the setting of wave `scale switch shaft 25 by knob 23. If desired rod 4I could engage the upper end of lever @I instead of the lower end. Station selector knob 39 is attached directly to condenser shaft I9 which carries the gear I9 meshing with rack bar I4.

In the modification shown in Figs. 10 and 11, a somewhat similar but more compact arrangement is shown in that the wave scale sheet 9, instead of being mounted at its lower end upon the rack bar III, has its upp-er end mounted thereon by clips Sy. This alteration requires the front and rear supporting panels 28 and II respectively to be spaced farther apart to accommodate the lowered positions of the wave scale sheet 9 and lamp housing 39 which latter is conveniently mounted directly upon the rear panel Ii as shown. Gear I9 which meshes with rack bar I4 is mounted behind panel I'I so as to avoid interference with lamp housing 34. The mechanism is further compacted by the use of an 'idler gear 39 interposed between gear 23 on shaft 22 Vand gear 29 which carries the irregularly conwindow 32; however other arrangements may be provided depending upon interior set construction.

Figs. 12 to 14 show an arrangement somewhat similar to that shown in Figs. 1 to 3, except that the tuning knobs 3l) and 25 on the wall 29 are disposed opposit-e each other and are offset to each side of the vertical axis of window 32 as shown in Fig. 14. In this modification the station selector knob 39, instead of being mounted directly upon shaft I9, is mounted upon a shaft 38 carrying a small reduction pinion 31 meshing with gear I8 which reciprocates rack bar I4. The use of reduction gearing between the shaft of knob 30 and condenser shaft I9 permits a very sensitive tuning adjustment. Shaft 38 may be disposed anywhere Within the arc C-D (Fig. 13) but would generally be located opposite the shaft 22 which carries knob 25, for panel symmetry. In the modication, shaft I9 does not extend through the wall 29 but carries the gear 2l) loosely mounted thereon, said gear having the irregularly contoured face ZI contacting with lower end of lever 9, as in Fig. 1. Shaft 22, which carries knob 25, may be disposed anywhere on arc C-E (Fig. 13). Shaft 22 has fixedly mounted thereon a gear 23 which meshes with the gear 29 whereby rotation of knob 25 will rotate the gear 20 and thereby focus the barrel I. Shaft 22 also carries a gear 24 meshing with gear 21 on the shaft 26 of the wave band switch (not shown). Shaft 26 may be disposed anywhere on arc F-G (Fig. 13) for any fixed position of shaft 22. The operation of the mechanism is otherwise the same as that described for the preceding modifications.

Figs. 15, 16 and 17 illustrate a modification of the mechanism also utilizing reducing gearing 3l on station selector shaft 38, an-d the arrangement in which the station selector knob 39 and wave band selector knob 25 are disposed in the same horizontal plane on the wall 29; but in this modification idler gear 39 (Figs. 16-17) is mounted on a stub shaft 159 and is interposed between the gear 29 which is loosely mounted on condenser shaft I9 and which carries the face cam ZI, and the gear 23 on shaft 22 carrying the knob 25 which controls the focusing of barrel I. Use cf the idler gear 39 (as in Fig. 10.) where the shafts I9 and 22 are relatively wid-ely separated permits a face cam 2l of minimum diameter to be used.

Figs. 18-19 show a still further' modification of the mechanism shown in Fig. 9 utilizing independent control for focusing the barrel. In the modification, instead of the knob i2 (shown in Fig. 9) an arm 50 is mounted on the threaded or spirally grooved rod III which moves axially in bearing IIa (when rotated) to adjust the setting of lever II. On the face of panel 29 are marked the ve positions, as at I, of the setting of arm 5I) to bring the barrel into focus upon each of the five wave scales 9a-9e inclusive of scale sheet 9. Knob 39 (Fig. 19) operates the rack bar I4 in the same manner described regarding Figs. 12 and 13; while the knob M3 operates the wave band switch of the mechanism. In this modification (as shown in Fig. 9) no knob 25 is used and certain gearing is dispensed with. In order to tune the mechanism pointer 5I) and knob M3 must always be set on the same number, viz., l, 2, etc., which numbers appear on the wall 29 adjacent the respective members.

Obviously many more modifications of the mechanism could be provided, and I do not limit my invention to the exact embodiments illustrated in the drawings, for obviously changes could be made therein within the scope of the claims.

I claim:

1. In combination with radio receiving apparatus provided with tuning mechanism; a sheet movably mounted in the apparatus and carrying a plurality of wave scales; means for moving the sheet as the tuning mechanism is adjusted; a sight barrel mounted to swing across the wave scales; and means for pivoting the barrel into focus with the particular wave scale corresponding with the adjustment of the tuning mechanism.

2. In a combination as set forth in claim 1, means for illuminating the portion of the sheet upon which the barrel is focused; and a fixed marker cooperating with the sheet.

3. In a combination as set forth in claim 1, said wave scale sheet being of transparent material; a casing mounted behind the sheet opposite the barrel .and having .a slot embracing all the wave scales; means for illuminating said casing; and a xed marker cooperating with the sheet.

4. In a combination as set forth in claim 1, said wave scale sheet being of transparent material; a casing mounted behind the sheet opposite the barrel and having a slot embracing all the wave scales; a lamp in said casing; a fixed marker associated with the sheet; and a xed translucent panel over the outer end of the barrel whereby the reading of the portion of the wave scale upon which the barrel is focused and the marker will be projected on the panel.

5. In a combination as set forth in claim 1, said wave scale sheet being of transparent material; a casing mounted behind the sheet opposite the barrel and having a slot embracing all the wave scales; a lamp in said casing; a fixed marker cooperating with the sheet; and magnifying means in the barrel whereby the reading of the portion of the wave scale upon which the barrel is focused and the marker will be magnified.

6. In a combination as set forth in claim 1, said wave scale sheet being of transparent material; a casing mounted behind the sheet opposite the barrel and having a slot embracing all the wave scales; a lamp in said casing; a fixed marker cooperating with the sheet; a fixed translucent panel over the outer end of the barrel; and magnifying means in the barrel whereby the reading of the portion of the wave scale upon which the barrel is focused and the marker will be enlarged and projected on the panel.

'7. In a combination as set forth in claim 1, said wave scale sheet being of transparent mate rial; a casing mounted behind the sheet opposite the barrel and having a slot embracing all the wave scales; a lamp in said casing; a fixed marker cooperating with the sheet; and a fixed arcuate panel of translucent material over the outer end of the barrel, the axis of curvature of the panel being coaxial with the axis of swing of the barrel; whereby the reading of the portion of the wave scale upon which the barrel is focused will be projected on the panel.

8. In a combination as set forth in claim 1, said Wave scale sheet being of transparent material; a casing mounted behind the sheet opposite the barrel and having a slot embracing all the wave scales; a lamp in said casing; a fixed marker cooperating with the sheet; a fixed arcuate panel of translucent material over the outer end of the barrel, the axis of curvature of the barrel being coaxial with the axis of swing of the barrel; and magnifying means in the barrel whereby the reading of the portion of the wave scale upon which the barrel is focused and marker will be enlarged and projected on the panel.

9. In a combination as set forth in claim 1, said wave scale sheet being substantially arcuate with its axis of curvature coaxial with the axis of swing of the barrel.

10. In a combination as set forth in claim 1, said wave scale sheet being formed of a series of plane surfaces embracing the respective scales, each plane surface being substantially tangent to the arc of a circle coaxial with the axis of swing of the barrel.

11, In a combination as set forth in claim 1, the respective wave scales of the sheet being of contrasting colors.

12. In combination with radio receiving apparatus having a casing provided with a window, and having an adjustable condenser tuning mechanism, and having a wave band switch; a sheet movably mounted in the apparatus behind the window and carrying a plurality of wave scales corresponding with the number of settings of the wave band switch; means for moving the sheet as the condenser is tuned to bring the corresponding portion of the sheet for such tuning opposite the window; a sight barrel pivotally mounted behind the window; and means for pivoting the barrel into focus with the particular wave scale of the sheet corresponding with the setting of the wave band switch.

13. In a combination as set forth in claim 12, a bar slidably mounted in the apparatus and carrying the wave scale sheet; said condenser tuning mechanism including a manually operated shaft; and said scale moving means comprising means actuated by said shaft for moving the bar.

14. In a combination as set forth in claim 12, a rack bar slidably mounted in the apparatus and carrying the wave scale sheet; said condenser tuning mechanism including a manually operated shaft; and said scale moving means comprising a gear on said shaft meshing with the rack bar.

15. In a combination as set forth in claim 12, a rack bar slidably mounted in the apparatus and carrying the wave scale sheet; said condenser tuning mechanism including a shaft; and said scale moving means comprising a manually operated shaft parallel with the condenser shaft; reduction gearing between the said shafts; and a gear on the condenser shaft meshing with the rack bar.

16. In a combination as set forth in claim 12, said wave band switch including a manually operated shaft; and said barrel focusing means comprising a pivoted lever supporting the free end of the barrel; and means operated by the shaft for pivoting the lever.

17. In a combination as set forth in claim 12, said wave band switch including a manually operated shaft; and said barrel focusing means comprising a pivoted lever supporting the free end of the barrel; and a cam rotated by the shaft and contacting with the lever.

18. In a combination as set forth in claim 12, a bar slidably mounted in the apparatus and carrying the wave scale sheet; said condenser tuning mechanism including a manually operated shaft; said scale moving means comprising means actuated by said shaft for moving the bar; said wave band switch including a second manually operated shaft; and said barrel focusing means comprising a pivoted lever supporting the free end of the barrel; and means operated by the second shaft for pivoting the lever.

19. In a combination as set forth Vin claim l2, a rack bar slidably mounted in the apparatus and carrying the Wave scale sheet; said condenser tuning mechanism including a manually operated shaft; said scale moving means comprising a gear on said shaft meshing with the rack bar; said. Wave band switch including a second manually operated shaft; said barrel focusing means comprising a pivoted lever supporting the free end of the barrel; and a cam rotated by the second shaft and contacting With the lever.

20. In a combination as set forth in claim 12, said Wave band switch including a rotatable knob; indicia denoting the setting of the switch; and said barrel vfocusing means comprising a pivoted lever supporting the free end of the barrel; a rotatable member adapted to shift the lever as the member is rotated; and indicia for denoting when the setting of the barrel corresponds With the set- 10 

